WyC,WyIL,WyJC: Removed assertXX bytecodes #377.
These bytecodes are now replaced with Assert blocks and Fail bytecodes.
This transformation is not yet complete.  Specifically, I still need to:
a) fixup DecisionTree; b) put back in loop invariants and
pre/post-conditions; c) make sure inlined invariants are put into an
Assert block.